| 摘要 |
PURPOSE:To prevent a concave spherical crystalline section from getting cracked by providing an inactive gas blow nozzle on a plane surface substrate section between a concave spherical surface and another spherical surface. CONSTITUTION:An inactive gas blow nozzle 4 is provided on a plane surface base section 3 between a concave spherical surface and another spherical surface on a crystalline base 1 having a plurality of concave spherical surfaces. Said blow nozzle can be of a form of a plurality of small holes of slit-type, and can be disposed at a right angle between the concave spherical surfaces or provided around the concave spherical surface. Said crystalline substrates 1 are disposed opposingly, and a gas feed nozzle 2 is provided at one end. In said structure, raw gas (for example, H2S gas and Zn vapor or the like) is fed from the blow nozzle 2, and inactive gas is blown off from the blow nozzle 4 during the gas phase synthesizing process. By said process, a crystalline with a hole corresponding to the blow nozzle 4 is grown on the crystalline base 1. When cooling after crystalline is grown, thermal stress generated by the difference of thermal expansion coefficient between the crystal and the base 1 is concentrated on around the hole of crystalline to generate cracks. As a result, cracks on the concave spherical surface section are prevented. |
